Threshold Volume Research Articles

Optimal Hospital and Surgeon Volume Thresholds to Improve 30-Day Readmission Rates, Costs, and Length of Stay for Total Hip Replacement

BackgroundLittle is known about whether there are optimal hospital and surgeon volume thresholds to reduce readmission, costs, and length of stay (LOS) for total hip replacement (THR). Nationwide population-based data were applied to identify the optimal hospital and surgeon volume thresholds and to discover the effects of these volume thresholds on 30-day unplanned readmission, costs and LOS for THR. MethodsA total of 6367 patients identified through Taiwan’s National Health Insurance Research Database received THR in 2012. Restricted cubic splines were used to identify the optimal hospital and surgeon volume needed to decrease the risk of 30-day unplanned readmission. Multilevel regression modeling and propensity score weighting were used to examine the impact of hospital and surgeon volume thresholds on 30-day unplanned readmission, costs, and LOS, after adjusting for patient, surgeon, and hospital characteristics. ResultsThe volume thresholds for hospitals and surgeons were 65 cases and 15 cases a year, respectively. The overall mean LOS was 7.3 ± 4.3 days. Patients who received THR from surgeons who did not reach the volume threshold had higher 30-day unplanned readmission rates, costs, and LOS than those who received THR from surgeons who reached the volume threshold. ConclusionThis is the first study to identify the surgeon volume threshold that can reduce 30-day unplanned readmission rates, costs, and LOS for THR. However, the results from Taiwan may not be applicable to other parts of the world. Identifying the threshold could help patients, providers, and policymakers to make decisions regarding optimal delivery of THR.

Poorer Speech Reception Threshold in Noise Is Associated With Lower Brain Volume in Auditory and Cognitive Processing Regions.

Purpose Hearing loss is associated with changes in brain volume in regions supporting auditory and cognitive processing. The purpose of this study was to determine whether there is a systematic association between hearing ability and brain volume in cross-sectional data from a large nonclinical cohort of middle-aged adults available from the UK Biobank Resource ( http://www.ukbiobank.ac.uk ). Method We performed a set of regression analyses to determine the association between speech reception threshold in noise (SRTn) and global brain volume as well as predefined regions of interest (ROIs) based on T1-weighted structural images, controlling for hearing-related comorbidities and cognition as well as demographic factors. In a 2nd set of analyses, we additionally controlled for hearing aid (HA) use. We predicted statistically significant associations globally and in ROIs including auditory and cognitive processing regions, possibly modulated by HA use. Results Whole-brain gray matter volume was significantly lower for individuals with poorer SRTn. Furthermore, the volume of 9 predicted ROIs including both auditory and cognitive processing regions was lower for individuals with poorer SRTn. The greatest percentage difference (-0.57%) in ROI volume relating to a 1 SD worsening of SRTn was found in the left superior temporal gyrus. HA use did not substantially modulate the pattern of association between brain volume and SRTn. Conclusions In a large middle-aged nonclinical population, poorer hearing ability is associated with lower brain volume globally as well as in cortical and subcortical regions involved in auditory and cognitive processing, but there was no conclusive evidence that this effect is moderated by HA use. This pattern of results supports the notion that poor hearing leads to reduced volume in brain regions recruited during speech understanding under challenging conditions. These findings should be tested in future longitudinal, experimental studies. Supplemental Material https://doi.org/10.23641/asha.7949357.

Pediatric resuscitation: Weight-based packed red blood cell volume is a reliable predictor of mortality.

The definition of massive transfusion (MT) in civilian pediatric trauma patients is not established. In combat-injured pediatric patients, the definition of MT is based on the volume of total blood products transfused. The aim of this study is to define MT in civilian pediatric trauma patients based on a packed red blood cell (PRBC) volume threshold and compare its predictive power to a total blood products volume threshold. An analysis of the pediatric American College of Surgeons Trauma Quality Improvement Program database was performed (2014-2016) including pediatric trauma patients (4-18 years) who received blood products within 24 hours. Receiver operator characteristic curves for predicting mortality determined the optimal PRBC MT threshold. Area under receiver operating characteristic curve (AUROC) curve analysis was performed to compare the predictive power of a PRBC threshold to a total blood product threshold. A total of 1,495 patients were included. Sensitivity and specificity for 24-hour and in-hospital mortality were optimal at a PRBC threshold of 20 mL/kg. As compared with total blood products threshold, 20 mL/kg PRBCs volume achieved higher discriminatory power for predicting 24-hour (AUROC, 0.803 vs. 0.672; p < 0.001) and in-hospital mortality (AUROC, 0.815 vs. 0.686, p < 0.001). Patients who received an MT had higher Injury Severity Score (p < 0.001) and were more likely to receive mechanical ventilation (p < 0.001) and intensive care unit admission (p < 0.001). Overall 24-hour mortality (23.1% vs. 7.6%, p < 0.001) and in-hospital mortality (44.9% vs. 15.8%, p < 0.001) were higher in the MT group. On regression analysis, MT significantly predicted in-hospital mortality (odds ratio, 3.8 [2.9-4.9, 95% CI]) and 24-hour mortality (odds ratio, 3.3 [2.4-4.7, 95% CI]). The use of a PRBCs MT definition in civilian pediatric patients is a better predictor of mortality compared with total blood products threshold. These results provide a framework for MT protocol development. Prognostic study, level III.

Hospital Operative Volume and Quality Indication for General Surgery Operations Performed Emergently in Geriatric Patients

Within the growing geriatric population, there is an increasing need for emergency operations. Optimizing outcomes can require a structured system of surgical care based on key quality indicators. To investigate this, the current study sought to answer 2 questions. First, to what degree does hospital emergency operative volume impact mortality for geriatric patients undergoing emergency general surgery (EGS) operations? Second, at what procedure-specific hospital volume will geriatric patients undergoing an emergency operation achieve at or better than average mortality risk? Retrospective cohort study of geriatric patients (aged 65 years and older) who underwent 1 of 10 EGS operations identified from the California State Inpatient Database (2010 to 2011). β-Logistic generalized linear regression was used, with the hospital as the unit of analysis, to investigate the relationship between hospital operative volume and in-hospital riskv-adjusted mortality. Hospital operative volume thresholds to optimize probability of survival were defined. There were 41,860 operations evaluated at 299 hospitals. For each operation, mortality decreased as hospital emergency operative volume increased (p < 0.001 for each operation); for every standardized increase in volume (meaning+1 natural logarithm of volume), the reduction in mortality ranged from 14% for colectomy to 61% for appendectomy. Hospital volume thresholds, which optimize to 95% probability of survival, varied by procedure, with a mean of 14 operations over 2 years. More than 50% of hospitals did not meet the threshold benchmarks, representing 22% of patients. Survival rates for geriatric patients were improved substantially when emergency operations were performed at hospitals with higher operative volumes. Consistent with all active Quality Programs of the American College of Surgeons, hospital operative volume appears to be an important metric of surgical quality for older patients undergoing emergency operations.

Anorectal pressures measured with high-resolution manometry in healthy people-Normal values and asymptomatic pelvic floor dysfunction.

High-resolution manometry (HRM) is used tomeasure rectoanal pressures in defecatory disorders and fecal incontinence. This study sought to define normal values for rectoanal HRM, ascertain the effects of age and BMI on rectoanal pressures, and compare pressures in asymptomatic women with normal and prolonged balloon expulsion time (BET). High-resolution manometry pressures and BET were measured in 163 asymptomatic healthy participants. Women (96) and men (47) with normal BET were used to estimate normal values and the effects of age/BMI on pressures using a Medtronic 4.2-mm-diameter rectoanal catheter. Age is associated with lower resting pressure, higher rectal pressure during evacuation, and a higher rectoanal gradient during evacuation in women and men. In women, the BET is also inversely correlated with age while the BMI is correlated with a higher threshold volume for discomfort and a longer BET. The anal squeeze pressure increment, squeeze duration, and HPZ length are higher in men than women. The rectoanal gradient during evacuation is also lower (ie, more negative) in asymptomatic women with an abnormal than a normal BET. These findings provide an expanded database of normal values for anorectal HRM in men and women. Age and sex affect anal resting and squeeze pressures, respectively; rectal pressure during evacuation is also higher in older people. Less than 15% of asymptomatic people have BET >60seconds, which is associated with manometry features of impaired evacuation.

Hospital Volume Threshold for the Treatment of Retroperitoneal Sarcoma.

Retroperitoneal sarcomas (RPS) are rare, histologically heterogeneous, and anatomically complex tumors. National Comprehensive Cancer Network guidelines recommend evaluation and management by multidisciplinary teams with experience in sarcoma. Our aim was to determine an appropriate hospital volume threshold for the treatment of RPS. Patients undergoing resection of RPS were identified from the National Cancer Data Base (1998-2012). Multivariable modeling with restricted cubic splines was employed to examine the association between hospital volume and survival and identify possible hospital volume threshold. The study included 5,340 patients who underwent surgery at 909 different hospitals. Median annual volume was two cases per year. After adjustment, hospital volume was associated with improved survival (p=0.01), without cutoff. The cohort was then grouped into: Low-volume (≤5 cases/year), intermediate-volume (6-10 cases/year), and high-volume (>10 cases/year). The majority of patients were treated in low-volume hospitals (86%), compared to 9% in intermediate- and 5% in high-volume centers; 44% of patients were treated in hospitals that performed one case per year. Compared to low-volume, high-volume hospitals more often had patients with high-grade and larger tumors. Adjusted 90-day mortality was significantly lower in high- vs. low-volume hospitals (odds ratio(OR)=0.25, p=0.02). With adjustment, treatment in high- vs. low-volume hospitals was associated with lower odds of margin positivity (OR=0.58, p=0.001), and improved overall survival (hazard ratio(HR)=0.61, p=0.002). Treatment of RPS in high-volume centers is associated with significant reduction in short-term mortality and improved long-term survival. Hospital volume may be a surrogate for the infrastructure and support necessary for the optimal management of these complex malignancies.

The Outcome of Cemented Acetabular Components in Total Hip Arthroplasty for Osteoarthritis Defines a Proficiency Threshold: Results of 22,956 Cases From the Australian Orthopaedic Association National Joint Replacement Registry

BackgroundThe declining popularity of cemented acetabular components is incongruous, given the published results of prostheses implanted using contemporary techniques. The outcome of arthroplasty has previously been demonstrated to correlate with surgeon experience and volume of practice. We aim to explore if surgeon volume alters outcomes of cemented acetabular components based on survivorship data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). MethodsAn observational study was undertaken using a cohort of 22,956 patients with a primary diagnosis of osteoarthritis in the period 2003-2016 in whom cemented acetabular components were implanted. The cohort was stratified by age (greater than or less than 65 years) and annualized surgical volume of ≤10, >10-≤25, and >25 cases. ResultsStratified by age and volume, there was a protective benefit against revision conveyed at volume thresholds of 10 cases per annum and 25 cases per annum for patients ≥65 years of age and <65 years of age, respectively. ConclusionCemented total hip arthroplasty has excellent survivorship out to 15 years based on AOANJRR data. This survivorship is further improved if surgeons perform a higher volume of cases, with >25 cases conferring the greatest benefit. The AOANJRR data set is used to define best practice; surgeons who choose to utilize cemented acetabular fixation should be encouraged to perform this technique in adequate volumes to minimize revision risk and ensure the preservation of this important surgical skill set.

Evaluation of the volume-value relationship in hip fracture care using evidence-based thresholds.

Studies have shown high-volume surgeons and hospitals deliver higher value care. The aims of this study were to establish meaningful thresholds defining high-volume surgeons and hospitals performing hip fracture surgery and to examine the relative market share of hip fracture cases using these surgeon and hospital strata. We performed a retrospective cohort study in a database of 103,935 patients undergoing hip fracture repair. We generated stratum-specific likelihood ratio (SSLR) models of a receiver operating characteristic (ROC) curve using length of stay (LOS) and cost value metrics. Volume thresholds predictive of decreased LOS and costs for surgeons and hospitals were identified. Analysis of annual surgeon hip fracture volume produced two volume categories for LOS and cost: 0-30 (low) and 31+ (high). Analysis of LOS by annual hospital hip fracture volume produced strata at: 0-59 (low), 60-146 (medium), and 147 or more (high). Analysis of cost by annual hospital volume produced strata at: 0-125 (low) and 126+ (high). LOS and cost both decreased significantly (p < 0.05) in progressively higher volume categories. Low-volume surgeons performed the majority of hip fracture cases, although they were performed at medium- or high-volume centres. This study demonstrates a direct relationship between volume and value, translating to improvement in hip fracture care delivery for both surgeons and hospitals. Higher volume hospitals while lower volume surgeons perform the majority of hip fracture cases, suggesting optimisation opportunities. However, systems-based practices at the hospital level likely drive value to a greater extent than individual surgeons.

Effects of esophageal acid infusion vs mosapride on distension-induced secondary peristalsis in humans.

Secondary peristalsis contributes to the clearance of the refluxate from the esophagus. Acute administration of 5-hydroxytryptamine 4 (5-HT4 ) receptors agonist, mosapride or esophageal infusion of hydrochloric acid (HCl) facilitates secondary peristalsis. The aim of this study was to determine whether esophageal acid infusion and administration of mosapride had different effects on secondary peristalsis. Secondary peristalsis was performed with esophageal distension with rapid and slow air injections in 16 healthy subjects. We performed two separate sessions with HCl (0.1 N) and 40 mg oral mosapride to compare their influence on secondary peristaltic parameters. The threshold volume of secondary peristalsis was significantly lower with HCl infusion than mosapride (P = 0.01) by slow air injections. The threshold volume to generate secondary peristalsis was significantly lower with HCl infusion than mosapride (P = 0.002) by rapid air injections. More secondary peristalsis was trigged by rapid air injections after HCl infusion than mosapride (P = 0.003). Infusion of HCl or mosapride administration has similar effects on peristaltic wave amplitude and duration of primary and secondary peristalsis. Acute esophageal acid infusion can induce greater mechanosensitivity to distension-induced secondary peristalsis than 5-HT4 receptors agonist mosapride. The data suggest that acid-sensitive afferents are more likely to contribute to sensory modulation of esophageal secondary peristalsis; however, the motility aspects of secondary peristalsis are comparable between acute esophageal acidification and 5-HT4 receptors activation via mosapride.

Bone SPECT-based segmented attenuation correction for quantitative analysis of bone metastasis (B-SAC): comparison with CT-based attenuation correction

BackgroundEvidence has shown the clinical usefulness of measuring the metastatic tumor burden of bone for prognostic assessment especially in prostate cancer; quantitative evaluation by dedicated SPECT is difficult due to the lack of attenuation correction (AC) method.We developed a novel method for attenuation correction using bone SPECT emission data (bone SPECT-based segmented attenuation correction; B-SAC) where emission data were virtually segmented into three tissues (i.e., bone, soft tissue, and air). Then, the pixel values in SPECT were replaced by 50 for the virtual soft tissue, and − 1000 for the virtual air. The replaced pixel values for the virtual bone were based on the averaged CT values of the normal vertebrae (B-SACN) or the metastatic bones (B-SACM). Subsequently, the processed SPECT data (i.e., SPECT value) were supposed to realize CT data (i.e., CT value) that were used for B-SAC. The standardized uptake values (SUVs) of 112 metastatic bone tumors in 15 patients with prostate cancer were compared between CTAC with scatter correction (SC) and resolution recovery (RR) and the following reconstruction conditions: B-SACN (+)SC(+)RR(+), B-SACM (+)SC(+)RR(+), uniform AC(UAC)(+)SC(+)RR(+), AC(−)SC(+)RR(+), and no correction (NC).ResultsThe SUVs in the five reconstruction conditions were all correlated with those in CTAC(+)SC(+)RR(+) (p < 0.01), and the correlations between B-SACN or B-SACM and CTAC images were excellent (r > 0.94). Bland-Altman analysis showed that the mean SUV differences between CTAC (+)SC(+)RR(+) and the other five reconstructions were 0.85 ± 2.25 for B-SACN (+)SC(+)RR(+), 1.61 ± 2.36 for B-SACM (+)SC(+)RR(+), 1.54 ± 3.84 for UAC(+)SC(+)RR(+), − 3.12 ± 4.97 for AC(−)SC(+)RR(+), and − 5.96 ± 4.59 for NC. Compared to CTAC(+)SC(+)RR(+), B-SACN (+)SC(+)RR(+) showed a slight but constant overestimation (approximately 17%) of the metastatic tumor burden of bone when the same threshold of metabolic tumor volume was used.ConclusionsThe results of this preliminary study suggest the potential for B-SAC to improve the quantitation of bone metastases in bone SPECT when X-ray CT or transmission CT data are not available. Considering the small but unignorable differences of lesional SUVs between CTAC and B-SAC, SUVs obtained with the current version of B-SAC seem difficult to be directly compared with those obtained with CTAC.

Blebbistatin reveals beneficial effects on the cystometric parameters in an animal model of detrusor overactivity

The aims of the study were to determine the effectiveness of blebbistatin (BLEB) on detrusor overactivity (DO) in an animal model induced by retinyl acetate (RA) and, because of potential urothelial permeability, to evaluate the degenerative impact of BLEB on the urothelium. Three days after RA instillation into the urinary bladder, BLEB was administered into the bladder and immediately after cystometric assessment was performed. Furthermore, Evans Blue extravasation into bladder tissue and urothelium thickness were measured. Sixty female Wistar rats were used and randomly assigned to one of four groups (n = 15 in each group): (1) control, (2) RA, (3) BLEB, and (4) RA + BLEB. RA administration induced changes in cystometric parameters reflecting DO, as previously reported. Treatment with BLEB did not significantly alter cystometric parameters in rats which did not receive RA. Administration of BLEB to rats pretreated with RA reversed changes in cystometric parameters induced by RA in basal pressure, threshold pressure, detrusor overactivity index, amplitude of nonvoiding contractions, frequency of nonvoiding contractions, voided volume, volume threshold, intercontraction interval, bladder compliance, and volume threshold to elicit nonvoiding contractions. There were no significant differences in Evans Blue extravasation into bladder tissue or urothelium thickness between the groups. The current research provides new data on the possible utility of blebbistatin in the pharmacotherapy of DO, which is an important feature of overactive bladder (OAB). Further studies in human patients with DO/OAB are warranted to confirm these preclinical results.

Endoscopic Endonasal Excision of Large and Giant Pituitary Adenomas: Radiological and Intraoperative Correlates of the Extent of Resection

Despite the superb visualization offered by the endoscopic endonasal transsphenoidal approach, the resection rates of large and giant pituitary adenomas have remained much lower than those of smaller macroadenomas. Various tumor characteristics can influence the extent of resection (EOR) and have been variably reported. Additional understanding of these factors is mandatory to improve the results. We analyzed the radiological and intraoperative tumor characteristics influencing the EOR in a cohort of patients with large and giant pituitary macroadenomas undergoing endoscopic endonasal transsphenoidal excision under our care. Twenty-eight patients were included. Magnetic resonance images were retrospectively analyzed for pre- and postoperative tumor volumetric analysis; preoperative tumor volume calculation using the formula (A× B× C/2); preoperative radioanatomical characteristics, including tumor shape, radiological structure, contrast enhancement, and extension; and the EOR. Intraoperative data were retrieved and included. The preoperative calculated tumor volume was 38.14 ± 23.02 cm3 and the preoperative measured tumor volume was 50.345 ± 17.36 cm3. A statistically significant difference was found between the calculated and measured tumor volumes for the whole cohort and for tumors with a maximum diameter >3.9 cm. A statistically significant difference in the EOR was found at a volume threshold of 26.2 cm3. Large cysts, heterogeneous enhancement, Knosp grade ≤2, soft tumor consistency, and tumor hemorrhage were significantly associated with gross total resection. Volumetric analysis should replace 2-dimensional methods in determining the size of large and giant pituitary adenomas. Specific tumor characteristics were associated with the EOR and could help in predicting the EOR for these tumors.

Increasing surgeon volume correlates with patient survival following open abdominal aortic aneurysm repair

ObjectiveThe annual number of open abdominal aortic aneurysm (AAA) repairs has decreased dramatically over the last decade, making the search for physician case volume thresholds more important. The purpose of this study was to identify a minimum threshold for annual surgeon case volume in open AAA repair. MethodsThe New York Statewide Planning and Research Cooperative System inpatient database was used to identify all patients undergoing open repair of an intact AAA between 2000 and 2008. Thirty-day survival was calculated using New York State vital records, which contain all New York State death certificates. The annual case volume for each surgeon was defined as the number of open AAA repairs performed in the year of the index procedure. The Contal and O'Quigley method was used to identify a minimum volume threshold. ResultsA total of 11,086 patients were included in the analysis. The selected cutpoint was six or more cases per year based on maximization of the Contal and O'Quigley test statistic. The high-volume group had comparable rates of cardiovascular comorbidities, but significantly improved 30-day and 5-year survival rates as well as shorter lengths of stay in the hospital. ConclusionsThis study identifies an ideal threshold for minimum annual surgeon case volume for open AAA repair. Over the study period, perioperative mortality would not have occurred in up to 150 patients if all procedures had been done by high-volume surgeons performing at least six repairs per year. However, even a minimum annual threshold of at least two repairs per year provided a mortality benefit. Ideal minimum volume thresholds should be developed using rigorous statistical analysis as well as local information about practice patterns.

Thresholds for identifying pathological intracranial pressure in paediatric traumatic brain injury

Intracranial pressure (ICP) monitoring forms an integral part of the management of severe traumatic brain injury (TBI) in children. The prediction of elevated ICP from imaging is important when deciding on whether to implement invasive ICP monitoring for a patient. However, the radiological markers of pathologically elevated ICP have not been specifically validated in paediatric studies. Here in, we describe an objective, non-invasive, quantitative method of stratifying which patients are likely to require invasive monitoring. A retrospective review of patients admitted to Cambridge University Hospital’s Paediatric Intensive Care Unit between January 2009 and December 2016 with a TBI requiring invasive neurosurgical monitoring was performed. Radiological biomarkers of TBI (basal cistern volume, ventricular volume, volume of extra-axial haematomas) from CT scans were measured and correlated with epochs of continuous high frequency variables of pressure monitoring around the time of imaging. 38 patients were identified. Basal cistern volume was found to correlate significantly with opening ICP (r = −0.53, p < 0.001). The optimal threshold of basal cistern volume for predicting high ICP (ge 20 mmHg) was a relative volume of 0.0055 (sensitivity 79%, specificity 80%). Ventricular volume and extra-axial haematoma volume did not correlate significantly with opening ICP. Our results show that the features of pathologically elevated ICP in children may differ considerably from those validated in adults. The development of quantitative parameters can help to predict which patients would most benefit from invasive neurosurgical monitoring and we present a novel radiological threshold for this.

Comparison of Different Images in Gross Target Volume Delineating on VX2 Nasopharyngeal Transplantation Tumor Models

Background: To determine optimum conditions for diagnosis of nasopharyngeal carcinoma, we established VX2 rabbit model to delineate gross target volume (GTV) in different imaging methods. Methods: The orthotopic nasopharyngeal carcinoma (NPC) was established in sixteen New Zealand rabbits. After 7-days inoculation, the rabbits were examined by CT scanning and then sacrificed for pathological examination. To achieve best delineation, different GTVs of CT, MRI, 18F-FDG PET/CT, and 18F-FLT PET/CT images were correlated with pathological GTV (GTVp). Findings: We found a 45% and 60% of the maximum standardized uptake value (SUVmax) as the optimal SUV threshold for the target volume of NPC in 18F-FDG PET/CT and 18F-FLT PET/CT images, respectively (GTVFDG45% and GTVFLT60%). Moreover, the GTVMRI and GTVCT were significantly higher than the GTVp (P ≤ 0.05), while the GTVFDG45% and especially GTVFLT60% were similar to the GTVp (R = 0.892 and R = 0.902, respectively; P ≤ 0.001). Interpretation: Notably, the results suggested that 18F-FLT PET/CT could reflect the tumor boundaries more accurately than 18F-FDG PET/CT, MRI and CT, which makes 18F-FLT PET-CT more advantageous for the clinical delineation of the target volume in NPC. Funding Statement: This research received financial support from the Scientific Research Project Fund of the Affiliated Hospital of Southwest Medical University (2013-60). Declaration of Interests: The authors have no financial interests related to the material in the manuscript. The authors declare that there are no conflicts of interest. Ethics Approval Statement: This study was approved by an independent ethics committee/institutional review board at Department of Oncology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China. All animal-related procedures and protocol were approved under the guidelines of the National Institutes of Health (NIH) Animal Care (1995, USA) and the local Ethics Committee guidelines by Institutional Animal Care and Treatment Committee of Southwest Medical University (Luzhou, China).

Defining “high volume center” for pancreaticoduodenectomy

Background: The relationship between hospital volume and patient outcomes for pancreaticoduodenectomy has been demonstrated by multiple studies. Various cutoffs to define a high-volume center have been used in the literature and these range from 1 to 20 cases per year. However, controversy exits regarding the validity of hospital volume and outcome association. The purpose of this study was to re-evaluate the previously utilized definitions using a large sample of patients undergoing pancreaticoduodenectomy to determine an objective, evidence based threshold of hospital volume associated with improvement in perioperative mortality. Methods: Patients who underwent pancreaticoduodenectomy were identified using the National Cancer Database from 2004 to 2015. The relationship between hospital volume and 90-day mortality was assessed using a logistic regression model. Receiver Operator Characteristic analysis was performed to determine hospital volume cutoff which maximized the linear combination of specificity and sensitivity as shown in Figure 1a. Results: 42,402 patients underwent pancreaticoduodenectomy at 1,238 unique hospitals. 30- and 90-day mortality of the study population were 3.33% (n = 1411) and 6.81% (n = 2889), respectively. Mean annual mortality of individual hospitals is shown in Figure 1b. A logistic regression was performed which showed that institutional volume is significantly associated with decreased overall 90-day mortality. The maximum improvement in 90-day mortality is seen if the annual hospital volume was greater than 9 (p < 0.0001, OR = 0.458 (0.399–0.525). When analysis is limited to hospitals that performed greater than 9 cases per year, the maximum improvement in 90-day mortality was reached at 36 cases per year (p < 0.0001, OR = 0.647 (0.595–0.702). Conclusion: Based on the association of hospital volume to 90-day mortality after pancreaticoduodenectomy in the National Cancer Database we recommend defining low-volume hospitals as those performing 1 to 9 pancreaticoduodenectomies per year, medium-volume as those performing 10 to 36, and high-volume as those performing over 36 pancreaticoduodenectomies per year. These recommendations will need to be validated with additional studies.

Evidence for an Upper Threshold for Resistance Training Volume in Trained Women

The purpose of the present study was to compare the effects of different volumes of resistance training (RT) on muscle performance and hypertrophy in trained women. The study included 40 volunteers that performed RT for 24 wk divided into groups that performed 5 (G5), 10 (G10), 15 (G15), and 20 (G20) sets per muscle group per session. Ten-repetition maximum (10RM) tests were performed for the bench press, lat pulldown, 45° leg press, and stiff-legged deadlift. Muscle thickness (MT) was measured using ultrasound at biceps brachii, triceps brachii, pectoralis major, quadriceps femoris, and gluteus maximus. All groups significantly increased all MT measures and 10RM tests after 24 wk of RT (P < 0.05). Between-group comparisons revealed no differences in any 10RM test between G5 and G10 (P > 0.05). G5 and G10 showed significantly greater 10RM increases than G15 for lat pulldown, leg press, and stiff-legged deadlift. 10RM changes for G20 were lower than all other groups for all exercises (P < 0.05). G5 and G10 showed significantly greater MT increases than G15 and G20 in all sites (P < 0.05). MT increased more in G15 than G20 in all sites (P < 0.05). G5 increases were higher than G10 for pectoralis major MT, whereas G10 showed higher increases in quadriceps MT than G5 (P < 0.05). Five to 10 sets per week might be sufficient for attaining gains in muscle size and strength in trained women during a 24-wk RT program. There appears no further benefit by performing higher exercise volumes. Because lack of time is a commonly cited barrier to exercise adoption, our data support RT programs that are less time consuming, which might increase participation and adherence.

Hospital Volume and Operative Mortality for General Surgery Operations Performed Emergently in Adults.

This study aimed to answer 2 questions: first, to what degree does hospital operative volume affect mortality for adult patients undergoing 1 of 10 common emergency general surgery (EGS) operations? Second, at what hospital operative volume threshold will nearly all patients undergoing an emergency operation realize the average mortality risk? Nontrauma surgical emergencies are an underappreciated public health crisis in the United States; redefining where such emergencies are managed may improve outcomes. The field of trauma surgery established regionalized systems of care in part because studies demonstrated a clear relationship between hospital volume and survival for traumatic emergencies. Such a relationship has not been well-studied for nontrauma surgical emergencies. Retrospective cohort study of all acute care hospitals in California performing nontrauma surgical emergencies. We employed a novel use of an ecological analysis with beta regression to investigate the relationship between hospital operative volume and mortality. A total of 425 acute care hospitals in California performed 165,123 EGS operations. Risk-adjusted mortality significantly decreased as volume increased for all 10 EGS operations (P < 0.001 for each); the relative magnitude of this inverse relationship differed substantially by procedure. Hospital operative volume thresholds were defined and varied by operation: from 75 cases over 2 years for cholecystectomy to 7 cases for umbilical hernia repair. Survival rates for nontrauma surgical emergencies were improved when operations were performed at higher-volume hospitals. The use of ecological analysis is widely applicable to the field of surgical outcomes research.

A randomised controlled trial of bag-valve-mask teaching techniques.

Bag-valve-mask (BVM) ventilation is a vital skill in the management of the collapsed patient; however, the quality of BVM ventilation is a cause for concern. Modified techniques, designed to be easier for the novice practitioner, offer an opportunity to improve quality. One such modification is the 'LASOO' (Lift, Apply, Slide, Oppose, Observe) approach, which offers theoretical benefits over the traditionally taught 'CE' (finger shapes) technique. We conducted a randomised controlled trial (RCT) to determine whether LASOO was superior to CE in terms of tidal volume, when taught to novices in the skills-lab setting. We conducted a randomised controlled trial (RCT) to determine whether LASOO was superior to CE in terms of tidal volume, when taught to novices in the skills-lab setting METHODS: A total of 76 undergraduate health care students received a manikin-based teaching session on LASOO or CE. They then delivered 20 breaths (10 with each hand) to a modified airway manikin. The primary outcome was mean tidal volume; secondary outcomes were the proportion of breaths that achieved 150-mL and 400-mL threshold volumes. Subgroup analyses and statistical modelling were conducted for time-point, hand dominance and hand size. The mean tidal volume was 320mL for CE and 304mL for LASOO. The median percentage of attempts that exceeded 150mL was 85 for CE and 82.5 for LASOO. The median percentage of attempts that exceeded 400mL was 20 for CE and 20 for LASOO. The differences recorded between the techniques were not statistically significant. There was a small, statistically significant increase in tidal volume across both techniques with time-point and holding the mask with the non-dominant hand. LASOO is a viable alternative to CE. Educators may opt to teach either or both techniques, allowing students to choose the technique that they prefer.

From the Circulation Family of Journals.

From the Circulation Family of Journals.