[The dynamic monitoring of gastric residual volume by ultrasound was used to guide the early nutritional treatment of patients with severe mechanical ventilation to gradually achieve the standard].

OBJECTIVE: To explore the application value of dynamic monitoring of gastric residual volume (GRV) in achieving different target energy in severe mechanical ventilation patients. METHODS: A prospective randomized controlled study was conducted. Forty-two patients with mechanical ventilation admitted to the department of critical care medicine of General Hospital of Ningxia Medical University from July to December 2022 were enrolled. According to the random number table method, patients were divided into GRV guided enteral nutrition by traditional gastric juice pumpback method (control group, 22 patients) and GRV guided enteral nutrition by bedside ultrasound (test group, 20 patients). General data were collected from both groups, and clinical indicators such as hypersensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6), neutrophil percentage (Neut%), procalcitonin (PCT), absolute lymphocytes (LYM), prealbumin (PA), and retinol-binding protein (RBP) were dynamically observed. Inflammation, infection, immunity, nutritional indicators, and the incidence of reflux/aspiration, ventilator-associated pneumonia (VAP) were compared between the two groups, and further compared the proportion of patients with respectively to reach the target energy 25%, 50%, and 70% on days 1, 3, and 5 of initiated enteral nutrition. RESULTS: (1) There were no significant differences in gender, age, body mass index (BMI), duration of mechanical ventilation, and acute physiology and chronic health evaluation II (APACHE II), sequential organ failure assessment (SOFA), severe nutritional risk score (NUTRIC) at admission between the two groups, indicating comparability. (2) On day 1 of initiated enteral nutrition, there were no significant differences in infection, inflammation, immunity and nutrition indicators between the two groups. On day 3 of initiated enteral nutrition, the hs-CRP in the test group was lower than that control group, LYM and PA were higher than those control group [hs-CRP (mg/L): 129.60±75.18 vs. 185.20±63.74, LYM: 1.00±0.84 vs. 0.60±0.41, PA (mg/L): 27.30±3.66 vs. 22.30±2.55, all P < 0.05]. On day 5 of initiated enteral nutrition, the hs-CRP, Neut%, PCT in the test group were lower than those control group, LYM and PA were higher than those control group [hs-CRP (mg/L): 101.70±54.32 vs. 148.40±36.35, Neut%: (85.50±7.66)% vs. (92.90±6.01)%, PCT (µg/L): 0.7 (0.3, 2.7) vs. 3.6 (1.2, 7.5), LYM: 1.00±0.68 vs. 0.50±0.38, PA (mg/L): 27.10±4.57 vs. 20.80 ± 3.51, all P < 0.05]. There were no significantly differences in IL-6 and RBP between the two groups at different time points. (3) The proportion of 50% and 70% of achieved target energy in the test group on day 3, day 5 of initiated enteral nutrition were higher than those of the control group (70.0% vs. 36.4%, 70.0% vs. 36.4%, both P < 0.05). (4) The incidence of reflux/aspiration and VAP in the test group on day 5 of initiated enteral nutrition were significantly lower than those control group (incidence of reflux/aspiration: 5.0% vs. 28.6%, incidence of VAP: 10.0% vs. 36.4%, both P < 0.05). CONCLUSIONS: Dynamic monitoring of GRV by bedside ultrasound can accurately improve the proportion of 50% of achieved target energy on day 3 and 75% on day 5 in severe mechanical ventilation patients, improve the patient's inflammation, immune and nutritional status, and can prevent the occurrence of reflux/aspiration and VAP.

The Impact of Positive Expiratory Pressure Therapy on Hyperinflation in Patients With COPD.

BACKGROUND: Lung hyperinflation is a typical clinical feature of patients with COPD. Given the association between breathing at elevated lung volumes and the manifestation of severe debilitating symptoms, therapeutic interventions such as positive expiratory pressure (PEP) therapy and its variations (temporary, oscillatory) have been devised to mitigate lung hyperinflation. However, the efficacy of these interventions remains to be conclusively demonstrated. METHODS: A systematic review with meta-analysis of randomized trials was conducted following the PRISMA guidelines. Seven databases were screened with no date or language restriction. Two authors independently applied eligibility criteria and assessed the risk of bias of included studies using the Cochrane risk-of-bias tool. Outcomes were lung hyperinflation measures detected through changes in inspiratory capacity (IC), functional residual capacity (FRC), total lung capacity (TLC), and residual volume (RV), as well as FEV1, FVC, dyspnea, and physical capacity. Pooled standardized mean differences (SMDs) or mean differences (MDs) and 95% CI were calculated using a random-effects model. RESULTS: Seven trials, all with a high risk of bias, were included. Compared to control group, RV significantly decreased (4 studies, n = 231; SMD -0.42 [95% CI -0.77 to -0.08], P = .02), dyspnea improved (n = 321, SMD -1.17 [95% CI -1.68 to -0.66], P < .001), and physical capacity increased (5 studies, n = 311; MD 30.1 [95% CI 19.2-41.0] m, P < .001) with PEP therapy. There was no significant difference between PEP therapy and the control group in TLC, FVC, or FEV1. Only one study reported changes in inspiratory capacity as well as FRC. CONCLUSIONS: In patients with COPD, the effect of PEP therapy on lung hyperinflation is unclear owing to the non-consistent change in lung hyperinflation outcomes, insufficient data, and lack of high-quality trials. Dyspnea and physical capacity might improve with PEP therapy.

Ultrasound evaluation of gastric residual volume in fasting end-stage renal failure patients.

STUDY OBJECTIVE: To evaluate the gastric contents and gastric residual volume in patient with end-stage renal failure by gastric ultrasound. DESIGN: Prospective observational study. SETTING: Tertiary care teaching hospital. PATIENTS: Adults of either gender with BMI < 40 kg/m2 with end-stage renal failure scheduled to undergo arteriovenous graft or fistula. INTERVENTIONS & MEASUREMENTS: The cross-sectional area of the gastric antrum was measured by gastric ultrasound with patient in both supine and right lateral decubitus positions. The volume of the gastric contents were calculated using suitable validated formula. In addition, the nature of the gastric contents was also determined by gastric ultrasound. MAIN RESULTS: The incidence of delayed gastric emptying was found to be 57.7% in the population studied despite following the prescribed preoperative standard fasting guidelines. CONCLUSIONS: There is a high incidence of delayed gastric emptying in patients with end-stage renal failure presenting for surgery which may predispose them to risk of pulmonary aspiration perioperatively.

Residual volume of extruded disc material and residual spinal cord compression measured on postoperative MRI do not predict neurological outcomes in dogs following decompressive surgery for thoracolumbar intervertebral disc extrusion.

Published studies on the validity of using quantitative MRI measures of pre- and postoperative spinal cord (SC) compression as prognostic indicators for dogs undergoing surgery for intervertebral disc extrusion (IVDE) are currently limited. The aim of this retrospective analytical study was to describe the volume of postoperative residual extradural material (VREM) and the ratio of the cross-sectional area (CSA) of maximum SC compression to the CSA of SC in a compression-free intervertebral space as MRI measures of preoperative and postoperative compression (residual spinal cord compression, RSCC), and to compare these measures between the neurological outcome in a group of dogs. Inclusion criteria were dogs that underwent surgery for thoracolumbar IVDE, were imaged pre- and immediately postoperatively by MRI, and had a neurological follow-up examination 2 to 5 weeks postoperatively. Two blinded observers independently performed measurements in pre- and postoperative MRI studies. Dogs were classified into positive outcome (PO) and negative outcome (NO) groups based on follow-up neurologic examination scores. Seventeen dogs were included (12 PO, 5 NO). Interobserver agreement for MRI measurements was good to excellent (ICCs: 0.76-0.97). The prevalence of residual extradural material in postoperative MRI studies was 100%. No significant differences in mean preoperative SC compression, mean RSCC, mean SC decompression, or VREM were found between outcome groups (P = .25; P = .28; P = .91, P = .98). In conclusion, neither postoperative VREM nor RSCC could predict successful neurological outcomes.

Deimplementation of Gastric Residual Volume Monitoring to Enhance Patient Nutrition.

BACKGROUND: Routine gastric residual volume monitoring remains common in nursing practice. However, current evidence supports using a focused nursing assessment to identify signs and symptoms of enteral feeding intolerance such as abdominal pain, abdominal distension, and vomiting. LOCAL PROBLEM: At the author's institution, nurses and other clinicians began reporting inconsistencies in gastric residual volume monitoring along with frequent interruptions in the delivery of enteral nutrition. INTERVENTIONS: The quality improvement project included patients in the medical intensive care unit receiving enteral nutrition. Gastric residual volume monitoring was eliminated. Instead, enteral nutrition was suspended on the basis of signs and symptoms of enteral feeding intolerance. Multimodal education was provided to nurses, nurse practitioners, and physicians caring for these patients. Formative evaluation occurred via staff rounds, summative evaluation occurred through a staff survey, and nutritional adequacy was evaluated by tracking patient weight. RESULTS: The 6-week project included 37 patients on the medical intensive care unit service. Of these patients, 28 gained weight; the mean change in weight was +6.2%. The practice change was well perceived by staff and is now an established part of care for any patient receiving enteral feedings at the study hospital. CONCLUSIONS: The deimplementation of routine gastric residual volume monitoring is supported by evidence. Use of a focused gastrointestinal nursing assessment to identify enteral feeding intolerance is safe, feasible, and effective and improves nutrition delivery and nurses' workflow.

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.

Effect of lying position on gastric residual volume in premature infants: A systematic review.

Premature infants' gastric residual volume may be affected by position. This systematic review was conducted to examine the effect of lying position on the gastric residual volume of preterm newborns fed by gastric tube. Electronic databases (PubMed, MEDLINE, MEDLINE Complete, Academic Search Ultimate, CINAHL Complete, Cochrane, and Scopus) were searched for randomized controlled experimental or quasiexperimental studies in English published between 2011 and 2022 investigating the effect of one or more lying positions on gastric residual volume in premature newborns. The PICOS strategy was used in preparing and reporting the systematic review. A total of 304 articles were retrieved, and the full texts of 12 articles were evaluated for suitability. After eliminating the excluded articles, 10 articles were included in the analysis. The quality of evidence varied, with four studies judged to have poor quality whereas the remaining six were considered to range from moderate to good in quality. Based on the results obtained from the studies, it was determined that gastric residual volume was the least in the right lateral and prone positions and more in the left lateral and supine positions compared with the other two positions, with no difference between the two latter positions. The methodological differences, such as the evaluation of different positions, the timing of positioning and the duration of maintaining in the same position, and the measurement times of gastric residual volume made it difficult to reach a definitive proof. We concluded that high-evidence studies evaluating all positions are needed.

Differences in residual volume above different tracheostomy tube cuffs depending on tube structure, tube tilt angle, and liquid viscosity.

INTRODUCTION: Proper management of aspirated material above the tracheostomy tube cuff is crucial to prevent complications, such as aspiration pneumonia. This study aimed to thoroughly examine the effects of aspirated liquid viscosity, suction port positioning, and tube tilt angle on residual volume above the cuff (RVAC). METHODS: Five types of tracheostomy tubes (approximately 9 mm outer diameter) were placed through a transparent cylinder with an inner diameter of 18 mm. The cuff was inflated to completely seal the interior of the cylinder. Four liquids with different viscosities were poured onto the cuff, and the liquid above the cuff was suctioned from the side port. The cylinder was angled at 90° and 20°, and each test was performed thrice to determine the average RVAC. RESULTS: After side-port suctioning, some liquid residue was observed on the cuff of all tracheostomy tubes. The RVAC increased with higher liquid viscosity. The tubes with a longer distance from the suction port opening to the cuff top exhibited more RVAC. Moreover, the RVAC was almost the same regardless of the cylinder angle for tubes with a suction port on the lateral side. However, tubes with backside ports showed a decreased RVAC with cylinder tilt. CONCLUSIONS: This study underscores the persistence of residual material on cuffed tracheostomy tubes even with regular subglottic secretion drainage. This emphasizes the need for specialized tracheostomy tube development aimed at reducing post-suction RVAC. Improved designs can potentially minimize complications associated with residue accumulation.

Agreement and Reliability of Patient-measured Postvoid Residual Bladder Volumes.

OBJECTIVE: To assess the reliability, agreement with provider measurement, and patient preferences regarding patient self-measurement of postvoid residual bladder volume (PVR). PVR measurement in the nonhealthcare setting is a valuable opportunity for remote monitoring of voiding dysfunction patients. We hypothesized that patient self-measurement of PVR using a smart-device portable ultrasound system with artificial intelligence would demonstrate high reliability, strong agreement with provider measurement, and be preferred over provider measurements. METHODS: Patients were enrolled during outpatient Urology visits. PVRs were measured in triplicate by providers using each of the following: an FDA-cleared (standard) bladder scanner, the portable ultrasound probe using ultrasound images (Butterfly US image mode), and the portable ultrasound probe using abstract images (Butterfly abstract mode). Subjects self-measured PVRs in triplicate using both imaging modes and reported their experiences via questionnaire. Reliability was assessed via intraclass correlation. Agreement between methods was assessed via Bland-Altman analyses using a clinically acceptable difference threshold of 50 mL. RESULTS: Fifty patients were enrolled. Intraclass correlations ranged from 0.95 to 0.98 for each method. 95% limits of agreement between standard bladder scanner and patient self-measurement were - 71.73 mL and 86.73 mL using Butterfly US image mode and - 93.84 mL and 112.52 mL using Butterfly abstract mode, respectively. Most patients preferred self-measurement over provider measurement (74% vs 26%, respectively). CONCLUSION: Patient self-measurement of PVR using smart-device integrated portable ultrasound probes is feasible, reliable, and preferred by patients. Limits of agreement between patient self-measurement and standard bladder scanner measurements exceeded our clinically acceptable difference threshold, though the inherent error of ultrasound-based bladder volume measurements should be considered. Longitudinal PVR assessments in nonhealthcare settings may facilitate remote monitoring of voiding dysfunction patients.

The effect of pre-endoscopy maltodextrin beverage on gastric residual volume and patient's well-being: a randomised controlled trial.

Prolonged fasting prior to oesophagogastroduodenoscopy (OGDS) could be noxious to patients' well-being. Strict fasting protocol has been used prior to OGDS with the concern of reduced visibility or suboptimal endoscopic assessment. Maltodextrin beverages were also commonly used as the pre-operative carbohydrate loading in enhanced recovery after surgery (ERAS) protocol. Our study aimed to look for the effects of maltodextrin beverage 2 h before OGDS on gastric residual volume and patient's well-being scores. This was a single-blinded, stratified randomised controlled trial, comparing control group (A, received 400 ml of plain water) and carbohydrate loading group (B, received 400 ml of Carborie). The primary objectives were to measure the gastric residual volume (GRV) and patient's well-being scores using visual analogue scale (VAS) scores for hunger, thirst, anxiety, tiredness and general discomfort. Of 80 randomised patients, 78 completed the study (38 received plain water and 40 Carborie). The median (IQR) GRV was not significantly different between group A and B (5.0 ml (20) vs 4.0 ml (19), p = 0.777). Both groups showed significant reduction in VAS scores in all five parameters (p ≤ 0.001). There were no complications attributed to endoscopy in either group. Pre-endoscopy maltodextrin beverage is as safe as clear water with improved patient's well-being in both groups.Clinical Trial Registration: NCT05106933.

The Effect of Residual Gastric Volume on Body Mass Index, Excess Weight Loss Rate and Metabolic Response after Sleeve Gastrectomy.

BACKGROUND/AIM: To investigate the metabolic response and body mass index reduction according to the remaining stomach volume between 6-12 months after the operation in patients who underwent sleeve gastrectomy surgery for obesity and to determine the relationship between the remaining stomach volume and metabolic improvement. Materials and Methods: Patients underwent sleeve gastrectomy in a single center by the same team and with the same standardized method. Residual gastric volumes were calculated from three-dimensional computed tomography images obtained 6-12 months postoperatively. BMI, excess weight loss (EWL), total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), very low density lipoprotein (VLDL), triglyceride, hemoglobin A1c (HbA1c), total protein, albumin values were recorded preoperatively and at the time of residual volume measurement. Results: There were 49 subjects with a mean SD preoperative BMI of 47.26+-6.21 kg/m2 and mean age 37.51+-10.88 years. Mean residual volume was 155.36+-56.71 cc. Residual volume was associated with postoperative mean BMI (28.44+-3.23 kg/m2; p 0.001) and postperative mean EWL%(29.27+-7.66; p=0.001). Residual gastric volume was also negative correlated with postoperative mean HbA1c (p=0.004). HbA1c (p=0.828), LDL (p=0.661), HDL (p=0.848), triglycerides (p=0.641), VLDL (p=0.794), total protein relation (p=0.539) and albumin (p=0.824) were analyzed before and after surgery and were not correlated with residual gastric volume. CONCLUSION: The smaller the residual gastric volume after laparoscopic sleeve gastrectomy, the higher the %EWL and the greater the decrease in HbA1c. This study show that laparoscopic sleeve gastrectomy is an effective surgical procedure in patients with Type 2 diabetes mellitus.

Ultrasound assessment of gastric residual volume in patients over 60 years of age undergoing gastroscopy under sedation: a prospective cohort study.

BACKGROUND: We aimed to assess the accuracy of ultrasonographic measurement of the antral cross-sectional area (CSA) in the preprocedural evaluation of gastric contents and volume in fasted patients > 60 yr of age scheduled for gastroscopy under sedation. METHODS: We included n = 81 patients > 60 yr of age and n = 79 younger controls scheduled to undergo elective gastroscopy in a prospective cohort study. A gastric ultrasound examination was performed to measure the antral CSA in both semisitting and right lateral decubitus (RLD) positions. Afterward, patients were graded using the Perlas qualitative grading scale. The actual gastric volume was endoscopically suctioned. Full stomach was defined as gastric volume > 1.5 mL·kg-1 and/or the presence of solid particles. We constructed receiver operating characteristic curves to determine the accuracy of ultrasonographic measurement of RLD CSA to detect a gastric volume > 1.5 mL·kg-1 and calculated the diagnostic test attributes of RLD CSA for the identification of a gastric volume > 1.5 mL·kg-1 RESULTS: The incidence of full stomach was 8/81 (9.8%) in patients > 60 yr of age and 1/79 (1.2%) in young patients (risk difference, 8.6%; 95% CI, 1.3 to 15.8; P = 0.03). The cut-off value of RLD CSA was 10.4 cm2 for the detection of gastric volume > 1.5 mL·kg-1 in patients > 60 yr of age, with a sensitivity of 75%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 98.6%. CONCLUSION: Patients > 60 yr of age scheduled for gastroscopy under sedation had a higher incidence of a full stomach detected with ultrasound compared with a younger cohort, which is potentially associated with a higher aspiration risk. We calculated a cut-off value of RLD CSA for detecting gastric volume in patients > 60 yr of age of approximately 10 cm2, which may help to quickly assess patients at risk of aspiration. TRIAL REGISTRATION: www.chictr.org.cn (ChiCTR2100048994); registered 19 July 2021.

RéSUMé: CONTEXTE: Notre objectif était d'évaluer la précision de la mesure échographique de la section transversale antrale (CSA) dans l'évaluation préprocédurale du contenu et du volume gastriques chez les patient·es à jeun > 60 ans devant bénéficier d'une gastroscopie sous sédation. MéTHODE: Nous avons inclus n = 81 patient·es > 60 ans et n = 79 patient·es témoins plus jeunes devant bénéficier d'une gastroscopie non urgente dans une étude de cohorte prospective. Une échographie gastrique a été réalisée pour mesurer la CSA antrale en position semi-assise et en décubitus latéral droit (DLD). Par la suite, la patientèle a été classée à l'aide de l'échelle de classement qualitatif de Perlas. Le volume gastrique réel était aspiré par endoscopie. Un estomac plein a été défini comme un volume gastrique > 1,5 mL·kg­1 et/ou la présence de particules solides. Nous avons construit des courbes de la fonction d'efficacité du récepteur (courbes ROC) afin de déterminer la précision de la mesure échographique de la CSA en DLD pour détecter un volume gastrique > 1,5 mL·kg­1 et calculé les attributs du test diagnostique de la CSA en DLD pour identifier un volume gastrique > 1,5 mL·kg­1. RéSULTATS: L'incidence d'estomac plein était de 8/81 (9,8 %) chez les patient·es > 60 ans et 1/79 (1,2 %) chez les patient·es jeunes (différence de risque, 8,6 %; IC 95 %, 1,3 à 15,8; P = 0,03). La valeur seuil de la CSA en DLD était de 10,4 cm2 pour la détection d'un volume gastrique > 1,5 mL·kg­1 chez la patientèle > 60 ans, avec une sensibilité de 75 %, une spécificité de 100 %, une valeur prédictive positive de 100 % et une valeur prédictive négative de 98,6 %. CONCLUSION: La patientèle > 60 ans devant bénéficier d'une gastroscopie sous sédation avait une incidence plus élevée d'estomac plein détecté par échographie par rapport à une cohorte plus jeune, ce qui est potentiellement associé à un risque d'aspiration plus élevé. Nous avons calculé une valeur seuil de la CSA en DLD pour détecter le volume gastrique chez les patient·es > 60 ans d'environ 10 cm2, ce qui peut aider à évaluer rapidement les personnes à risque d'aspiration. ENREGISTREMENT DE L'éTUDE: www.chictr.org.cn (ChiCTR2100048994); enregistrée le 19 juillet 2021.

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.

A threshold for mitotic activity and post-surgical residual volume defines distinct prognostic groups for astrocytoma IDH-mutant.

AIMS: The distinction between CNS WHO grade 2 and grade 3 is instrumental in choosing between observational follow-up and adjuvant treatment for resected astrocytomas IDH-mutant. However, the criteria of CNS WHO grade 2 vs 3 have not been updated since the pre-IDH era. METHODS: Maximal mitotic activity in consecutive high-power fields corresponding to 3 mm2 was examined for 118 lower-grade astrocytomas IDH-mutant. The prognostic value for time-to-treatment (TTT) and overall survival (OS) of mitotic activity and other putative prognostic factors (including age, performance status, pre-surgical tumour volume, multilobar involvement, post-surgical residual tumour volume and midline involvement) was assessed for tumours with ATRX loss and the absence of CDKN2A homozygous deletion or CDK4 amplification, contrast enhancement, histological necrosis and microvascular proliferation. RESULTS: Seventy-one per cent of the samples had <6 mitoses per 3 mm2 . Mitotic activity, residual volume and multilobar involvement were independent prognostic factors of TTT. The threshold of ≥6 mitoses per 3 mm2 identified patients with a shorter TTT (median 18.5 months). A residual volume ≥1 cm3 also identified patients with a shorter TTT (median 24.5 months). The group defined by <6 mitoses per 3 mm2 and a residual volume <1 cm3 had the longest TTT (median 73 months) and OS (100% survival at 7 years). These findings were confirmed in a validation cohort of 52 tumours. CONCLUSIONS: Mitotic activity and post-surgical residual volume can be combined to evaluate the prognosis for patients with resected astrocytomas IDH-mutant. Patients with <6 mitoses per 3 mm2 and a residual volume <1 cm3 were the best candidates for observational follow-up.

Residual amniotic fluid volume predicts the sealing of preterm prelabor rupture of fetal membranes in the pre- and periviable period.

OBJECTIVE: Preterm prelabor rupture of fetal membranes (pPROM) is a leading cause of preterm birth. When pPROM occurs around the pre- and periviable period, the perinatal outcome is unfavorable. However, there have been a few cases in which the leakage of amniotic fluid ceases and the ruptured fetal membranes are spontaneously sealed. MATERIALS AND METHODS: The prognosis of 38 cases of pPROM at less than 27 weeks of gestation in Kyoto University Hospital were studied. The clinical factors related to the sealing of fetal membranes were investigated. RESULTS: Spontaneous sealing was confirmed in five patients (13%), and sealing occurred within 14 days of pPROM. Women in the no sealing group delivered at 26.3 ± 0.5 weeks of gestation, whereas women in the sealing group delivered at term at 38.8 ± 0.4 weeks (p < 0.0001). The maximum vertical pocket (MVP) of amniotic fluid at the time of pPROM diagnosis was 2.2 ± 0.3 cm in the no sealing group and 3.8 ± 0.5 cm in the sealing group (p = 0.043). All cases of sealing occurred when the MVP at diagnosis was more than 2 cm, and there were no cases of sealing if the MVP at diagnosis was less than 2 cm. In addition, the value of C-reactive protein at ROM was less than 0.4 mg/dL in all cases in the sealing group. CONCLUSION: The residual volume of sterile amniotic fluid at the onset of pPROM may predict the possibility of fetal membrane sealing.

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.

Routine versus no assessment of gastric residual volumes in preterm infants receiving enteral feeding via intermittent feeding tubes: a randomized controlled trial.

OBJECTIVE: To evaluate whether eliminating routine gastric residual volume (GRV) assessments would lead to quicker attainment of full feeding volumes in preterm infants. STUDY DESIGN: This is a prospective randomized controlled trial of infants ≤32 weeks gestation and birthweight ≤1250 g admitted to a tertiary care NICU. Infants were randomized to assess or not assess GRV before enteral tube feedings. The primary outcome was time to attain full enteral feeding volume defined as 120 ml/kg/day. The Wilcoxon rank sum test was used to compare the days to reach full enteral feeds between the two groups. RESULTS: 80 infants were randomized, 39 to the GRV assessing and 41 to the No-GRV assessing group. A predetermined interim analysis at 50% enrollment showed no difference in primary outcome and the study was stopped as recommended by the Data Safety Monitoring Committee. There was no significant difference in median days to reach full enteral feeds between the two groups [GRV assessment: 12d (5) vs. No-GRV assessment:13d (9)]. There was no mortality in either group, one infant in each group developed necrotizing enterocolitis stage 2 or greater. CONCLUSION: Eliminating the practice of gastric residual volume assessment before feeding did not result in shorter time to attain full feeding.

The minimal important difference of the constant work rate cycle test in severe COPD.

BACKGROUND: The Constant Work Rate Cycle Test (CWRT) is a commonly used and sensitive test to detect treatment success in patients with Chronic Obstructive Pulmonary Disease (COPD). Earlier, the Minimal Important Difference (MID) of the CWRT was estimated at 101 s (or 34%) change from baseline based on one well executed study. However, this study was performed in a population of patients with mild-to-moderate COPD, and we have learned that MIDs might be quite different in patients with severe COPD. Therefore, we aimed to establish the MID of the CWRT in patients with severe COPD. METHODS: We included 141 patients with severe COPD, who underwent either pulmonary rehabilitation, bronchoscopic lung volume reduction with endobronchial valves, or a sham bronchoscopy as a control group. CWRT workload was set at 75% of the peak work capacity, as determined by an incremental cycle test. We used the change in 6-min walking test (6-MWT), forced expiratory volume in 1s (FEV1), residual volume (RV), and St. George's Respiratory Questionnaire (SGRQ) total score as anchors to calculate the MID. RESULTS: All anchors had an association of ≥0.41 with change in CWRT. The MID estimates for the different anchors were: 6-MWT 278 s (95%), FEV1 273 s (90%), RV 240 s (84%), and SGRQ 208 s (71%). The average of these four MID estimates resulted in an MID of 250 s (or 85%). CONCLUSION: We established the MID for CWRT at 250 s (or 85%) change from baseline in patients with severe COPD.